Abstract

Coupled mode theory (CM) is widely applied in integrated optics, while the rigorous Local Mode theory (LM) is less known, being somewhat harder to implement. We compare the two theories in determining polarization coupling inside a laminated rib waveguide made of a-Si:H and SiO2.For moderate optical axis slant (low hybridization) and for fixed layer thickness the two theories show similar results but LM becomes mandatory when hybridization is important.

Abstract

Coupled mode theory (CM) is widely applied in integrated optics, while the rigorous Local Mode theory (LM) is less known, being somewhat harder to implement. We compare the two theories in determining polarization coupling inside a laminated rib waveguide made of a-Si:H and SiO2.For moderate optical axis slant (low hybridization) and for fixed layer thickness the two theories show similar results but LM becomes mandatory when hybridization is important.